U.S. patent application number 10/948108 was filed with the patent office on 2006-03-23 for method of decoding barcode symbols and the like using multiple scanning lines.
Invention is credited to Kazukuni Hosoi, Haruo Matsuoka.
Application Number | 20060060654 10/948108 |
Document ID | / |
Family ID | 36072870 |
Filed Date | 2006-03-23 |
United States Patent
Application |
20060060654 |
Kind Code |
A1 |
Hosoi; Kazukuni ; et
al. |
March 23, 2006 |
Method of decoding barcode symbols and the like using multiple
scanning lines
Abstract
The present invention provides a method of encoding a barcode,
in which the barcode is scanned at multiple scanning lines along
plural length portions to determine potential locations where the
bars probably exist. For each potential length, data obtained at
all the scanning lines is synthesized to determine the validity of
the location. The plural length portions are then combined to
ascertain the information.
Inventors: |
Hosoi; Kazukuni; (Saitama
Pref., JP) ; Matsuoka; Haruo; (Saitama Pref.,
JP) |
Correspondence
Address: |
KAPLAN GILMAN GIBSON & DERNIER L.L.P.
900 ROUTE 9 NORTH
WOODBRIDGE
NJ
07095
US
|
Family ID: |
36072870 |
Appl. No.: |
10/948108 |
Filed: |
September 23, 2004 |
Current U.S.
Class: |
235/462.12 ;
235/462.08 |
Current CPC
Class: |
G06K 7/10554 20130101;
G06K 7/1093 20130101; G06K 7/10861 20130101 |
Class at
Publication: |
235/462.12 ;
235/462.08 |
International
Class: |
G06K 7/10 20060101
G06K007/10 |
Claims
1. A method of reading a barcode formed by parallel bars and
spaces, comprising the steps of: scanning, at different scanning
lines, along a length of said barcode, to determine potential
locations along said length where said bars probably exist; for
each length scanned, combining data obtained by said scanning at
all of said different scanning lines to detect data, and combing
the data detected along each length with data detected along other
lengths of said bar to obtain complete data.
2. The method of claim 1, wherein said different scanning lines are
parallel to each other.
3. The method of claim 2, wherein said barcode is scanned at said
different scanning lines simultaneously.
4. The method of claim 2, wherein said barcode is scanned by an
image area sensor or area scanner.
5. The method of claim 2, wherein said barcode is scanned along
said scanning lines line by line.
6. The method of claim 1, wherein said potential location is
determined to be valid when a majority of said data obtained at all
said different scanning lines shows that a bar exists.
7. The method of claim 6, wherein said barcode is scanned at three
or more different scanning lines.
8. The method of claim 1, wherein said potential location is
determined to be valid when an average of said data obtained at all
said different scanning lines shows that a bar exists.
9. The method of claim 1, wherein said barcode is a 1-D
barcode.
10. The method of claim 9, wherein said 1-D barcode is a
constituent element of a multi dimensional barcode.
11. A method of decoding a barcode, comprising the steps of:
scanning said barcode along multiple scanning lines and along
predetermined lengths to obtain data at all said multiple scanning
lines along said length; ascertaining data along each of said
lengths by combining information from plural lines; for each of
said potential lengths, using said data obtained from all said
multiple scanning lines and associated to said each location to
verify said each location in accordance with a predetermined
scheme; and decoding said barcode by combining data from plural
lengths.
12. The method of claim 11, wherein said scanning is carried out by
an image area reader or area scanner.
13. The method of claim 11, wherein there are at least three said
scanning lines.
14. The method of claim 13, wherein said predetermined scheme is
such that, for said each length portion, a majority of said data
obtained from all said scanning lines is utilized to determine the
data.
15. The method of claim 11, wherein each of said potential
locations is determined if said data in said each location obtained
at any of said multiple scanning lines shows that said character of
said barcode exists.
Description
FIELD OF THE INVENTION
[0001] This invention relates to techniques of decoding barcodes,
and more particularly, to a method of decoding a 1-D barcode in
which the barcode is scanned at multiple scanning lines so as to
read and decode barcodes of low quality, poor readability and/or
having one or more defects by potentially using information from
different horizontal portions of different scan lines to piece the
together the equivalent of a single scan line.
BACKGROUND OF THE INVENTION
[0002] 1-D barcodes are universally used to provide information in
a machine-readable format, such as the well-known Universal Product
Code (UPC) strip on a product package. A 1-D barcode is usually
formed by bars and spaces arranged in parallel along a length of
the barcode, and the encoded information is represented by the
arrangement of the bars and the spaces, and in particular, by the
locations along the length of the barcode where the bars exist. To
read the barcode, the varying widths of the bars, and the spaces
between the bars, are measured and interpreted to extract the
data.
[0003] However, the barcode is difficult to correctly read when the
barcode is defective or not clear. For example, as shown in FIG.
1(a), if a defect in the form of a tilted line 11 runs across the
bars 1, the point 12 where the tilted line 11 meets with the
scanning line 2 may be improperly taken by the scanner as a
location where a bar exists. In FIG. 2(a), some of the bars 1a in
the barcode 10 are broken or are not clear enough, and will be
erroneously read as spaces by the scanner if the scanning line 2
runs through the missing or unclear portions of the defective bars
1a. Additionally, if the barcode is beneath an uneven transparent
covering material such as a plastic wrapper, the barcode may not be
correctly read.
[0004] Therefore, there exists a need to improve the reliability in
reading a barcode, especially when the barcode is defective or has
poor readability.
SUMMARY OF THE INVENTION
[0005] The present invention provides a method of encoding a
barcode in which the barcode is scanned along multiple scanning
lines along a length of the barcode to determine potential
locations where the bars probably exist. For each potential
location, data obtained at all the scanning lines are analyzed in
combination to determine the validity of the location. Thus, the
defective barcode with poor readability can still be correctly read
since most of the scanning lines may run across the good portions
of the defective bars.
[0006] In a preferred embodiment, the barcode is scanned by an
image area reader or area scanner. Preferably, there are at least
three scanning lines, and for each potential location found by the
scanning, the majority of the data obtained at all the scanning
lines determines the data. Then, the determination at each location
is used in combination with the determination at other locations to
fully decode the information. In other enhanced embodiments, other
combinations in addition to a "majority rules" decision may be
utilized.
DESCRIPTION OF THE DRAWINGS
[0007] The above and other advantages and features of the present
invention will be clearer after reading the detailed description of
preferred embodiments of the present invention with reference to
the accompanying drawings in which:
[0008] FIGS. 1(a) and 1(b) illustrate the problems existing with
the conventional methods in reading defective barcode symbols;
and
[0009] FIGS. 2(a) and 2(b) illustrate that the method of the
present invention solves the problems in FIGS. 1(a) and 1(b).
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0010] According to the present invention, the barcode is scanned
along multiple scanning lines instead of using only one single
scanning line in the conventional method. Preferably, the scanning
lines are generally parallel to each other. In an embodiment as
illustrated in FIGS. 2(a) and 2(b), the barcode 10 is scanned along
three scanning lines 2, 3 and 4. Obviously, more scanning lines can
be used to increase the reliability. This can be done by means of
an image area reader or area scanner. The barcode 10 can be scanned
at the multiple scanning lines 2,3, 4 simultaneously or can be
scanned line by line.
[0011] As shown in FIG. 2(a), which corresponds to FIG. 1(a) where
a tilted line 11 runs across the barcode 10, with the three
scanning lines 2, 3 and 4 used according to the present invention,
the tilted line 11 meets with the scanning lines 2, 3 and 4 at
points 12, 13 and 14 respectively. Thus, from the reading result of
the scanning, a bar may exist at each of the locations
corresponding to points 12, 13 and 14, which would be a final
conclusion in the prior art if only a single scanning line is
used.
[0012] However, according to the method of the present invention,
for each of the above potential locations determined by the points
12, 13 and 14, the data obtained in all the three scanning lines 2,
3 and 4 are combined to determine the actual presence of the bars
at these locations according to a predetermined technique. In a
preferred embodiment, majority decision rule is adopted to
ascertain the information at the location. More specifically, with
respect to a specific location, if the majority of the scanning
lines indicate that there is a bar, the location is determined to
contain a bar, while if more scanning lines indicate that there is
no bar, the location is determined to not contain a bar.
[0013] For example, as to the location corresponding to point 12,
the data obtained at scanning lines 3 and 4 shows that there is no
bar found at points 12a and 12b corresponding to the location.
Similarly, as to the location corresponding to point 14, the data
obtained at the scanning lines 2 and 3 indicates that there is no
bar at corresponding points 14a and 14b. According to the majority
decision rule, the locations corresponding to points 12 and 14 are
determined invalid and there is no bar running across the points 12
and 14.
[0014] As to point 13 where the scanning line 13 happens to meet
with a bar 1, the data obtained at other two scanning lines 2 and 4
also indicates that a bar may exist at the location corresponding
to the point 13. Thus, the location corresponding to point 13 is
validated, and there is a bar existing at the location
corresponding to point 13 and running through point 13. For all
other bars 1, the data read at all three scanning lines 2, 3 and 4
is the same, and the locations where the bars 1 exist can be thus
determined. When scanning is complete, the information can be
compiled from piecing together the information gathered at each
location using the foregoing technique. After all the locations are
determined, the barcode is decoded according to the techniques
well-known in the art.
[0015] It is also notable that other techniques of combining the
plural scanning lines in addition to a "majority rules" decision
may be utilized. For example, the system could require that at
least four out of five show the presence of the bar. Or, the system
could combine the light levels received when reading all of the
bars and determine the presence of a bar if and when the combined
signals from all the scanning lines exceed a predetermined
threshold. Therefore, with the teaching of the present invention,
the tilted line 11 or other imperfections do not result in an
incorrect interpretation of the data.
[0016] FIG. 2(b) illustrates the situation similar to FIG. 1(b)
where some of the bars are not clear or are partially missing. For
example, the middle portion of bar 1a is missing, and the scanning
line 2 runs through the missing middle portion of bar 1a. In the
prior art as shown in FIG. 1(b), bar 1a will be found not existing.
However, according to the teachings of the present invention, two
other scanning lines 3 and 4 run across the good portions of bar
1a, and the data obtained at the meeting points 31a and 41a
indicates that there may exist a bar at the location corresponding
to the points 31a and 41a. Even though the data read at scanning
line 2 shows that there is no bar existing at such location,
according to the majority decision rule, the location is deemed to
contain a valid bar since more scanning lines show that there is a
bar at the location.
[0017] Similarly, defective bar 1b can be determined to be there
from the data obtained at the scanning lines 2 and 4 even though
the scanning line 3 does not detect bar 1b. Thus, the location
corresponding to the meeting points 21b and 41b is validated by the
fact that more scanning lines (2 and 4) show that there is a
bar.
[0018] Though the preferred embodiments of the invention have been
described above in detail, it is understood that adaptations and
modifications are possible to a person of ordinary skill in the art
without departing from the spirit and scope of the invention. For
example, the 1-D barcode may be a constituent part of a stacked
barcode, and a variety of one and two dimensional barcodes may be
utilized. Instead of the majority decision rule, an average
calculation of the data obtained at a specific location by all the
scanning lines may be used. Thus, the scope of the present
invention is solely defined by the accompanying claims.
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